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kernel/arch/x86/boot/compressed/eboot.c
eabdullin e45b724fb0 Import of kernel-4.18.0-553.72.1.el8_10
2025-09-05 13:45:48 +00:00

1087 lines
28 KiB
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/* -----------------------------------------------------------------------
*
* Copyright 2011 Intel Corporation; author Matt Fleming
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* ----------------------------------------------------------------------- */
#include <linux/efi.h>
#include <linux/pci.h>
#include <linux/ctype.h>
#include <asm/efi.h>
#include <asm/e820/types.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/boot.h>
#include <asm/kaslr.h>
#include <asm/sev.h>
#include "../string.h"
#include "eboot.h"
#include "../../../../drivers/firmware/efi/libstub/efistub.h"
#include "../../../../drivers/firmware/efi/libstub/x86-stub.h"
static efi_system_table_t *sys_table;
static const efi_dxe_services_table_t *efi_dxe_table;
static efi_memory_attribute_protocol_t *memattr;
static struct efi_config *efi_early;
__pure const struct efi_config *__efi_early(void)
{
return efi_early;
}
#define BOOT_SERVICES(bits) \
static void setup_boot_services##bits(struct efi_config *c) \
{ \
efi_system_table_##bits##_t *table; \
\
table = (typeof(table))sys_table; \
\
c->runtime_services = table->runtime; \
c->boot_services = table->boottime; \
c->text_output = table->con_out; \
}
BOOT_SERVICES(32);
BOOT_SERVICES(64);
void efi_char16_printk(efi_system_table_t *table, efi_char16_t *str)
{
efi_call_proto(efi_simple_text_output_protocol, output_string,
efi_early->text_output, str);
}
static efi_status_t
preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
{
struct pci_setup_rom *rom = NULL;
efi_status_t status;
unsigned long size;
uint64_t romsize;
void *romimage;
/*
* Some firmware images contain EFI function pointers at the place where
* the romimage and romsize fields are supposed to be. Typically the EFI
* code is mapped at high addresses, translating to an unrealistically
* large romsize. The UEFI spec limits the size of option ROMs to 16
* MiB so we reject any ROMs over 16 MiB in size to catch this.
*/
romimage = efi_table_attr(efi_pci_io_protocol, romimage, pci);
romsize = efi_table_attr(efi_pci_io_protocol, romsize, pci);
if (!romimage || !romsize || romsize > SZ_16M)
return EFI_INVALID_PARAMETER;
size = romsize + sizeof(*rom);
status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to allocate memory for 'rom'\n");
return status;
}
memset(rom, 0, sizeof(*rom));
rom->data.type = SETUP_PCI;
rom->data.len = size - sizeof(struct setup_data);
rom->data.next = 0;
rom->pcilen = pci->romsize;
*__rom = rom;
status = efi_call_proto(efi_pci_io_protocol, pci.read, pci,
EfiPciIoWidthUint16, PCI_VENDOR_ID, 1,
&rom->vendor);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to read rom->vendor\n");
goto free_struct;
}
status = efi_call_proto(efi_pci_io_protocol, pci.read, pci,
EfiPciIoWidthUint16, PCI_DEVICE_ID, 1,
&rom->devid);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to read rom->devid\n");
goto free_struct;
}
status = efi_call_proto(efi_pci_io_protocol, get_location, pci,
&rom->segment, &rom->bus, &rom->device,
&rom->function);
if (status != EFI_SUCCESS)
goto free_struct;
memcpy(rom->romdata, romimage, romsize);
return status;
free_struct:
efi_call_early(free_pool, rom);
return status;
}
/*
* There's no way to return an informative status from this function,
* because any analysis (and printing of error messages) needs to be
* done directly at the EFI function call-site.
*
* For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
* just didn't find any PCI devices, but there's no way to tell outside
* the context of the call.
*/
static void setup_efi_pci(struct boot_params *params)
{
efi_status_t status;
void **pci_handle = NULL;
efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
unsigned long size = 0;
struct setup_data *data;
efi_handle_t h;
int i;
status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL,
&pci_proto, NULL, &size, pci_handle);
if (status == EFI_BUFFER_TOO_SMALL) {
status = efi_call_early(allocate_pool,
EFI_LOADER_DATA,
size, (void **)&pci_handle);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to allocate memory for 'pci_handle'\n");
return;
}
status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL, &pci_proto,
NULL, &size, pci_handle);
}
if (status != EFI_SUCCESS)
goto free_handle;
data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
while (data && data->next)
data = (struct setup_data *)(unsigned long)data->next;
for_each_efi_handle(h, pci_handle, size, i) {
efi_pci_io_protocol_t *pci = NULL;
struct pci_setup_rom *rom;
status = efi_call_early(handle_protocol, h,
&pci_proto, (void **)&pci);
if (status != EFI_SUCCESS || !pci)
continue;
status = preserve_pci_rom_image(pci, &rom);
if (status != EFI_SUCCESS)
continue;
if (data)
data->next = (unsigned long)rom;
else
params->hdr.setup_data = (unsigned long)rom;
data = (struct setup_data *)rom;
}
free_handle:
efi_call_early(free_pool, pci_handle);
}
static void retrieve_apple_device_properties(struct boot_params *boot_params)
{
efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
struct setup_data *data, *new;
efi_status_t status;
u32 size = 0;
void *p;
status = efi_call_early(locate_protocol, &guid, NULL, &p);
if (status != EFI_SUCCESS)
return;
if (efi_table_attr(apple_properties_protocol, version, p) != 0x10000) {
efi_printk(sys_table, "Unsupported properties proto version\n");
return;
}
efi_call_proto(apple_properties_protocol, get_all, p, NULL, &size);
if (!size)
return;
do {
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size + sizeof(struct setup_data), &new);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to allocate memory for 'properties'\n");
return;
}
status = efi_call_proto(apple_properties_protocol, get_all, p,
new->data, &size);
if (status == EFI_BUFFER_TOO_SMALL)
efi_call_early(free_pool, new);
} while (status == EFI_BUFFER_TOO_SMALL);
new->type = SETUP_APPLE_PROPERTIES;
new->len = size;
new->next = 0;
data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
if (!data) {
boot_params->hdr.setup_data = (unsigned long)new;
} else {
while (data->next)
data = (struct setup_data *)(unsigned long)data->next;
data->next = (unsigned long)new;
}
}
efi_status_t efi_adjust_memory_range_protection(unsigned long start,
unsigned long size)
{
efi_status_t status;
efi_gcd_memory_space_desc_t desc;
unsigned long end, next;
unsigned long rounded_start, rounded_end;
unsigned long unprotect_start, unprotect_size;
rounded_start = rounddown(start, EFI_PAGE_SIZE);
rounded_end = roundup(start + size, EFI_PAGE_SIZE);
if (memattr != NULL) {
status = efi_call_proto(efi_memory_attribute_protocol,
clear_memory_attributes, memattr,
rounded_start,
rounded_end - rounded_start,
EFI_MEMORY_XP);
if (status != EFI_SUCCESS)
efi_printk(sys_table,
"Failed to clear EFI_MEMORY_XP attribute\n");
return status;
}
if (efi_dxe_table == NULL)
return EFI_SUCCESS;
/*
* Don't modify memory region attributes, they are
* already suitable, to lower the possibility to
* encounter firmware bugs.
*/
for (end = start + size; start < end; start = next) {
status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
if (status != EFI_SUCCESS)
break;
next = desc.base_address + desc.length;
/*
* Only system memory is suitable for trampoline/kernel image placement,
* so only this type of memory needs its attributes to be modified.
*/
if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
(desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
continue;
unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
unprotect_size = min(rounded_end, next) - unprotect_start;
status = efi_dxe_call(set_memory_space_attributes,
unprotect_start, unprotect_size,
EFI_MEMORY_WB);
if (status != EFI_SUCCESS) {
efi_printk(sys_table,
"WARNING: Unable to unprotect memory range\n");
break;
}
}
return EFI_SUCCESS;
}
static efi_char16_t *efistub_fw_vendor(void)
{
unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor,
sys_table);
return (efi_char16_t *)vendor;
}
static const efi_char16_t apple[] = L"Apple";
static void setup_quirks(struct boot_params *boot_params)
{
if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
!memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
retrieve_apple_device_properties(boot_params);
}
/*
* See if we have Universal Graphics Adapter (UGA) protocol
*/
static efi_status_t
setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
{
efi_status_t status;
u32 width, height;
void **uga_handle = NULL;
efi_uga_draw_protocol_t *uga = NULL, *first_uga;
efi_handle_t handle;
int i;
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)&uga_handle);
if (status != EFI_SUCCESS)
return status;
status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL,
uga_proto, NULL, &size, uga_handle);
if (status != EFI_SUCCESS)
goto free_handle;
height = 0;
width = 0;
first_uga = NULL;
for_each_efi_handle(handle, uga_handle, size, i) {
efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
u32 w, h, depth, refresh;
void *pciio;
status = efi_call_early(handle_protocol, handle,
uga_proto, (void **)&uga);
if (status != EFI_SUCCESS)
continue;
efi_call_early(handle_protocol, handle, &pciio_proto, &pciio);
status = efi_call_proto(efi_uga_draw_protocol, get_mode, uga,
&w, &h, &depth, &refresh);
if (status == EFI_SUCCESS && (!first_uga || pciio)) {
width = w;
height = h;
/*
* Once we've found a UGA supporting PCIIO,
* don't bother looking any further.
*/
if (pciio)
break;
first_uga = uga;
}
}
if (!width && !height)
goto free_handle;
/* EFI framebuffer */
si->orig_video_isVGA = VIDEO_TYPE_EFI;
si->lfb_depth = 32;
si->lfb_width = width;
si->lfb_height = height;
si->red_size = 8;
si->red_pos = 16;
si->green_size = 8;
si->green_pos = 8;
si->blue_size = 8;
si->blue_pos = 0;
si->rsvd_size = 8;
si->rsvd_pos = 24;
free_handle:
efi_call_early(free_pool, uga_handle);
return status;
}
void setup_graphics(struct boot_params *boot_params)
{
efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
struct screen_info *si;
efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
efi_status_t status;
unsigned long size;
void **gop_handle = NULL;
void **uga_handle = NULL;
si = &boot_params->screen_info;
memset(si, 0, sizeof(*si));
size = 0;
status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL,
&graphics_proto, NULL, &size, gop_handle);
if (status == EFI_BUFFER_TOO_SMALL)
status = efi_setup_gop(NULL, si, &graphics_proto, size);
if (status != EFI_SUCCESS) {
size = 0;
status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL,
&uga_proto, NULL, &size, uga_handle);
if (status == EFI_BUFFER_TOO_SMALL)
setup_uga(si, &uga_proto, size);
}
}
static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
{
efi_call_early(exit, handle, status, 0, NULL);
unreachable();
}
/*
* Because the x86 boot code expects to be passed a boot_params we
* need to create one ourselves (usually the bootloader would create
* one for us).
*
* Any error results in a call to the Exit() EFI boot service.
*/
struct boot_params *make_boot_params(struct efi_config *c)
{
struct boot_params *boot_params;
struct apm_bios_info *bi;
struct setup_header *hdr;
efi_loaded_image_t *image;
void *options, *handle;
efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
int options_size = 0;
efi_status_t status;
char *cmdline_ptr;
u16 *s2;
u8 *s1;
int i;
unsigned long ramdisk_addr;
unsigned long ramdisk_size;
efi_early = c;
sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
handle = (void *)(unsigned long)efi_early->image_handle;
/* Check if we were booted by the EFI firmware */
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
efi_exit(handle, EFI_INVALID_PARAMETER);
if (efi_early->is64)
setup_boot_services64(efi_early);
else
setup_boot_services32(efi_early);
status = efi_call_early(handle_protocol, handle,
&proto, (void *)&image);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
efi_exit(handle, status);
}
status = efi_low_alloc(sys_table, 0x4000, 1,
(unsigned long *)&boot_params);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to allocate lowmem for boot params\n");
efi_exit(handle, status);
}
memset(boot_params, 0x0, 0x4000);
hdr = &boot_params->hdr;
bi = &boot_params->apm_bios_info;
/* Copy the second sector to boot_params */
memcpy(&hdr->jump, image->image_base + 512, 512);
/*
* Fill out some of the header fields ourselves because the
* EFI firmware loader doesn't load the first sector.
*/
hdr->root_flags = 1;
hdr->vid_mode = 0xffff;
hdr->boot_flag = 0xAA55;
hdr->type_of_loader = 0x21;
/* Convert unicode cmdline to ascii */
cmdline_ptr = efi_convert_cmdline(sys_table, image, &options_size);
if (!cmdline_ptr) {
status = EFI_INVALID_PARAMETER;
goto fail;
}
hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
/* Fill in upper bits of command line address, NOP on 32 bit */
boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
hdr->ramdisk_image = 0;
hdr->ramdisk_size = 0;
/*
* Disregard any setup data that was provided by the bootloader:
* setup_data could be pointing anywhere, and we have no way of
* authenticating or validating the payload.
*/
hdr->setup_data = 0;
/* Clear APM BIOS info */
memset(bi, 0, sizeof(*bi));
status = efi_parse_options(cmdline_ptr);
if (status != EFI_SUCCESS)
goto fail2;
status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", hdr->initrd_addr_max,
&ramdisk_addr, &ramdisk_size);
if (status != EFI_SUCCESS &&
hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
efi_printk(sys_table, "Trying to load files to higher address\n");
status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", -1UL,
&ramdisk_addr, &ramdisk_size);
}
if (status != EFI_SUCCESS)
goto fail2;
hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
hdr->ramdisk_size = ramdisk_size & 0xffffffff;
boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
boot_params->ext_ramdisk_size = (u64)ramdisk_size >> 32;
return boot_params;
fail2:
efi_free(sys_table, options_size, hdr->cmd_line_ptr);
fail:
efi_free(sys_table, 0x4000, (unsigned long)boot_params);
efi_exit(handle, status);
}
static void add_e820ext(struct boot_params *params,
struct setup_data *e820ext, u32 nr_entries)
{
struct setup_data *data;
efi_status_t status;
unsigned long size;
e820ext->type = SETUP_E820_EXT;
e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
e820ext->next = 0;
data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
while (data && data->next)
data = (struct setup_data *)(unsigned long)data->next;
if (data)
data->next = (unsigned long)e820ext;
else
params->hdr.setup_data = (unsigned long)e820ext;
}
static efi_status_t
setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
{
struct boot_e820_entry *entry = params->e820_table;
struct efi_info *efi = &params->efi_info;
struct boot_e820_entry *prev = NULL;
u32 nr_entries;
u32 nr_desc;
int i;
nr_entries = 0;
nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
for (i = 0; i < nr_desc; i++) {
efi_memory_desc_t *d;
unsigned int e820_type = 0;
unsigned long m = efi->efi_memmap;
#ifdef CONFIG_X86_64
m |= (u64)efi->efi_memmap_hi << 32;
#endif
d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
switch (d->type) {
case EFI_RESERVED_TYPE:
case EFI_RUNTIME_SERVICES_CODE:
case EFI_RUNTIME_SERVICES_DATA:
case EFI_MEMORY_MAPPED_IO:
case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
case EFI_PAL_CODE:
e820_type = E820_TYPE_RESERVED;
break;
case EFI_UNUSABLE_MEMORY:
e820_type = E820_TYPE_UNUSABLE;
break;
case EFI_ACPI_RECLAIM_MEMORY:
e820_type = E820_TYPE_ACPI;
break;
case EFI_LOADER_CODE:
case EFI_LOADER_DATA:
case EFI_BOOT_SERVICES_CODE:
case EFI_BOOT_SERVICES_DATA:
case EFI_CONVENTIONAL_MEMORY:
if (efi_soft_reserve_enabled() &&
(d->attribute & EFI_MEMORY_SP))
e820_type = E820_TYPE_SOFT_RESERVED;
else
e820_type = E820_TYPE_RAM;
break;
case EFI_ACPI_MEMORY_NVS:
e820_type = E820_TYPE_NVS;
break;
case EFI_PERSISTENT_MEMORY:
e820_type = E820_TYPE_PMEM;
break;
default:
continue;
}
/* Merge adjacent mappings */
if (prev && prev->type == e820_type &&
(prev->addr + prev->size) == d->phys_addr) {
prev->size += d->num_pages << 12;
continue;
}
if (nr_entries == ARRAY_SIZE(params->e820_table)) {
u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
sizeof(struct setup_data);
if (!e820ext || e820ext_size < need)
return EFI_BUFFER_TOO_SMALL;
/* boot_params map full, switch to e820 extended */
entry = (struct boot_e820_entry *)e820ext->data;
}
entry->addr = d->phys_addr;
entry->size = d->num_pages << PAGE_SHIFT;
entry->type = e820_type;
prev = entry++;
nr_entries++;
}
if (nr_entries > ARRAY_SIZE(params->e820_table)) {
u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
add_e820ext(params, e820ext, nr_e820ext);
nr_entries -= nr_e820ext;
}
params->e820_entries = (u8)nr_entries;
return EFI_SUCCESS;
}
static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
u32 *e820ext_size)
{
efi_status_t status;
unsigned long size;
size = sizeof(struct setup_data) +
sizeof(struct e820_entry) * nr_desc;
if (*e820ext) {
efi_call_early(free_pool, *e820ext);
*e820ext = NULL;
*e820ext_size = 0;
}
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)e820ext);
if (status == EFI_SUCCESS)
*e820ext_size = size;
return status;
}
static efi_status_t allocate_e820(struct boot_params *params,
struct setup_data **e820ext,
u32 *e820ext_size)
{
unsigned long map_size, desc_size, buff_size;
struct efi_boot_memmap boot_map;
efi_memory_desc_t *map;
efi_status_t status;
__u32 nr_desc;
boot_map.map = &map;
boot_map.map_size = &map_size;
boot_map.desc_size = &desc_size;
boot_map.desc_ver = NULL;
boot_map.key_ptr = NULL;
boot_map.buff_size = &buff_size;
status = efi_get_memory_map(sys_table, &boot_map);
if (status != EFI_SUCCESS)
return status;
nr_desc = buff_size / desc_size;
if (nr_desc > ARRAY_SIZE(params->e820_table)) {
u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
if (status != EFI_SUCCESS)
return status;
}
return EFI_SUCCESS;
}
struct exit_boot_struct {
struct boot_params *boot_params;
struct efi_info *efi;
bool is64;
};
static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg,
struct efi_boot_memmap *map,
void *priv)
{
const char *signature;
__u32 nr_desc;
efi_status_t status;
struct exit_boot_struct *p = priv;
signature = p->is64 ? EFI64_LOADER_SIGNATURE : EFI32_LOADER_SIGNATURE;
memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
p->efi->efi_systab = (unsigned long)sys_table_arg;
p->efi->efi_memdesc_size = *map->desc_size;
p->efi->efi_memdesc_version = *map->desc_ver;
p->efi->efi_memmap = (unsigned long)*map->map;
p->efi->efi_memmap_size = *map->map_size;
#ifdef CONFIG_X86_64
p->efi->efi_systab_hi = (unsigned long)sys_table_arg >> 32;
p->efi->efi_memmap_hi = (unsigned long)*map->map >> 32;
#endif
return EFI_SUCCESS;
}
static efi_status_t exit_boot(struct boot_params *boot_params,
void *handle, bool is64)
{
unsigned long map_sz, key, desc_size, buff_size;
efi_memory_desc_t *mem_map;
struct setup_data *e820ext = NULL;
__u32 e820ext_size = 0;
efi_status_t status;
__u32 desc_version;
struct efi_boot_memmap map;
struct exit_boot_struct priv;
map.map = &mem_map;
map.map_size = &map_sz;
map.desc_size = &desc_size;
map.desc_ver = &desc_version;
map.key_ptr = &key;
map.buff_size = &buff_size;
priv.boot_params = boot_params;
priv.efi = &boot_params->efi_info;
priv.is64 = is64;
status = allocate_e820(boot_params, &e820ext, &e820ext_size);
if (status != EFI_SUCCESS)
return status;
/* Might as well exit boot services now */
status = efi_exit_boot_services(sys_table, handle, &map, &priv,
exit_boot_func);
if (status != EFI_SUCCESS)
return status;
/* Historic? */
boot_params->alt_mem_k = 32 * 1024;
status = setup_e820(boot_params, e820ext, e820ext_size);
if (status != EFI_SUCCESS)
return status;
return EFI_SUCCESS;
}
static bool have_unsupported_snp_features(void)
{
u64 unsupported;
unsupported = snp_get_unsupported_features(sev_get_status());
if (unsupported) {
efi_printk(sys_table,
"Unsupported SEV-SNP features detected\n");
return true;
}
return false;
}
static void efi_get_seed(void *seed, int size)
{
efi_get_random_bytes(sys_table, size, seed);
/*
* This only updates seed[0] when running on 32-bit, but in that case,
* seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
*/
*(unsigned long *)seed ^= kaslr_get_random_long("EFI");
}
static void error(char *str)
{
efi_printk(sys_table, "Decompression failed: ");
efi_printk(sys_table, str);
efi_printk(sys_table, "\n");
}
static const char *cmdline_memmap_override;
static efi_status_t parse_options(const char *cmdline)
{
static const char opts[][14] = {
"mem=", "memmap=", "efi_fake_mem=", "hugepages="
};
for (int i = 0; i < ARRAY_SIZE(opts); i++) {
const char *p = strstr(cmdline, opts[i]);
if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
cmdline_memmap_override = opts[i];
break;
}
}
return efi_parse_options(cmdline);
}
static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
{
unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
unsigned long addr, alloc_size, entry;
efi_status_t status;
u32 seed[2] = {};
/* determine the required size of the allocation */
alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
MIN_KERNEL_ALIGN);
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !nokaslr()) {
u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
static const efi_char16_t ami[] = L"American Megatrends";
efi_get_seed(seed, sizeof(seed));
virt_addr += (range * seed[1]) >> 32;
virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
/*
* Older Dell systems with AMI UEFI firmware v2.0 may hang
* while decompressing the kernel if physical address
* randomization is enabled.
*
* https://bugzilla.kernel.org/show_bug.cgi?id=218173
*/
if (sys_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
!memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
seed[0] = 0;
} else if (cmdline_memmap_override) {
efi_printk(sys_table,
"cmdline memmap override detected on the kernel command line - disabling physical KASLR\n");
seed[0] = 0;
}
boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
}
status = efi_random_alloc(sys_table,
alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
seed[0], EFI_LOADER_CODE,
LOAD_PHYSICAL_ADDR,
EFI_X86_KERNEL_ALLOC_LIMIT);
if (status != EFI_SUCCESS)
return status;
entry = decompress_kernel((void *)addr, virt_addr, error);
if (entry == ULONG_MAX) {
efi_free(sys_table, alloc_size, addr);
return EFI_LOAD_ERROR;
}
*kernel_entry = addr + entry;
return efi_adjust_memory_range_protection(addr, kernel_total_size);
}
static void __noreturn enter_kernel(unsigned long kernel_addr,
struct boot_params *boot_params)
{
/* enter decompressed kernel with boot_params pointer in RSI/ESI */
asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
unreachable();
}
/*
* On success, this routine will jump to the relocated image directly and never
* return. On failure, it will exit to the firmware via efi_exit() instead of
* returning.
*/
void __noreturn efi_main(struct efi_config *c,
struct boot_params *boot_params)
{
efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
efi_loaded_image_t *image;
struct setup_header *hdr = &boot_params->hdr;
unsigned long kernel_entry;
efi_status_t status;
void *handle;
efi_system_table_t *_table;
bool is64;
extern char _bss[], _ebss[];
/*
* Clear BSS. It might not have been cleared if we got here via
* the EFI handover protocol. No harm to clear it again if we
* got here via the EFI PE entry.
*/
memset(_bss, 0, _ebss - _bss);
efi_early = c;
_table = (efi_system_table_t *)(unsigned long)efi_early->table;
handle = (void *)(unsigned long)efi_early->image_handle;
is64 = efi_early->is64;
boot_params_ptr = boot_params;
sys_table = _table;
/* Check if we were booted by the EFI firmware */
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
efi_exit(handle, EFI_INVALID_PARAMETER);
if (is64)
setup_boot_services64(efi_early);
else
setup_boot_services32(efi_early);
if (have_unsupported_snp_features())
efi_exit(handle, EFI_UNSUPPORTED);
if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
efi_dxe_table = get_efi_config_table(sys_table, EFI_DXE_SERVICES_TABLE_GUID);
if (efi_dxe_table &&
efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
efi_printk(sys_table, "Ignoring DXE services table: invalid signature\n");
efi_dxe_table = NULL;
}
}
/* grab the memory attributes protocol if it exists */
efi_call_early(locate_protocol, &guid, NULL, (void **)&memattr);
status = efi_setup_5level_paging();
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "efi_setup_5level_paging() failed!\n");
goto fail;
}
/*
* make_boot_params() may have been called before efi_main(), in which
* case this is the second time we parse the cmdline. This is ok,
* parsing the cmdline multiple times does not have side-effects.
*/
#ifdef CONFIG_CMDLINE_BOOL
status = parse_options(CONFIG_CMDLINE);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to parse options\n");
goto fail;
}
#endif
if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
((u64)boot_params->ext_cmd_line_ptr << 32));
status = parse_options((char *)cmdline_paddr);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to parse options\n");
goto fail;
}
}
status = efi_decompress_kernel(&kernel_entry);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to decompress kernel\n");
goto fail;
}
/*
* If the boot loader gave us a value for secure_boot then we use that,
* otherwise we ask the BIOS.
*/
if (boot_params->secure_boot == efi_secureboot_mode_unset)
boot_params->secure_boot = efi_get_secureboot(sys_table);
/* Ask the firmware to clear memory on unclean shutdown */
efi_enable_reset_attack_mitigation(sys_table);
efi_random_get_seed(sys_table);
efi_retrieve_tpm2_eventlog(sys_table);
setup_graphics(boot_params);
setup_efi_pci(boot_params);
setup_quirks(boot_params);
status = exit_boot(boot_params, handle, is64);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "exit_boot() failed!\n");
goto fail;
}
/*
* Call the SEV init code while still running with the firmware's
* GDT/IDT, so #VC exceptions will be handled by EFI.
*/
sev_enable(boot_params);
efi_5level_switch();
enter_kernel(kernel_entry, boot_params);
fail:
efi_printk(sys_table, "efi_main() failed!\n");
efi_exit(handle, status);
}
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